Get full list of columns in check column of VerificationResult.checkResultsAsDataFrame.

**Is your feature request related to a problem? Please describe.**
Hello, is there a way to get a full list of columns in the constraint column of the checkResultsAsDataFrame dataframe? I am trying to join the VerificationResult.checkResultsAsDataFrame with VerificationResult.successMetricsAsDataFrame but it is impossible unless I can get a full list of the columns used for each constraint in checkResultsAsDataFrame. If there is a multicolumn constraint, the check value is **Stream**(column1, ?) so I can't see all the columns. This is very frustrating because I need all the values from both dataframes to give the best results on my project. I have attached a photo showing the stream example.

**Describe the solution you'd like**

The most ideal solution would be a dataframe with the all the columns from both successMetrics and checkResults. If that can't be done, if you could allow a full list of column names in the constraint column instead of stream, I think I can manipulate it to join.


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Inizia con VerificationResult.checkResultsAsDataFrame e VerificationResult.successMetricsAsDataFrame, quindi traccia come i vincoli multicolonna diventano Stream(column1, ?). Riproduci gli output del dataframe riportati nell’issue e determina come esporre tutte le colonne dei vincoli per le join; il lavoro è completo quando i vincoli multicolonna forniscono informazioni sulle colonne utilizzabili per le join o un dataframe combinato.

Scritto dal modello di indicizzazione a partire dal testo della issue.